物理化学学报 >> 2007, Vol. 23 >> Issue (07): 983-986.doi: 10.3866/PKU.WHXB20070704

研究论文 上一篇    下一篇

室温熔盐二(三氟甲基磺酸酰)亚胺锂-尿素体系的分子动力学模拟

李姝; 刘磊; 曹臻; 汪继强; 言天英   

  1. 南开大学材料化学系,新能源材料化学研究所, 天津 300071; 天津电源研究所, 天津 300381; 南开大学科学计算研究所, 天津 300071
  • 收稿日期:2006-11-22 修回日期:2007-03-05 发布日期:2007-07-03
  • 通讯作者: 言天英 E-mail:tyan@nankai.edu.cn

Molecular Dynamics Simulation on a Eutectic Systemof LiTFSI/Urea

LI Shu; LIU Lei; CAO Zhen; WANG Ji-Qiang; YAN Tian-Ying   

  1. Institute of New Energy Material Chemistry, Department of Materials Chemistry, Nankai University, Tianjin 300071, P. R. China; Tianjin Institute of Power Sources, Tianjin 300381, P. R. China; Institute of Scientific Computing, Nankai University, Tianjin 300071, P. R. China
  • Received:2006-11-22 Revised:2007-03-05 Published:2007-07-03
  • Contact: YAN Tian-Ying E-mail:tyan@nankai.edu.cn

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摘要： 应用分子动力学模拟了25 ℃和50 ℃时新型室温熔盐二(三氟甲基磺酸酰)亚胺锂[LiN(SO2CF3)2, LiTFSI]与尿素(摩尔比为1:3.6)体系的结构与动力学性质. 在两个温度下体系的微观结构基本相同, Li+的配位数约为5, 且都是与溶剂和阴离子中的氧原子发生配位. 对TFSI-的研究表明, 每个TFSI-只提供四个氧中的一个与Li+配位; 而且在Li+的配位层中, TFSI-具有顺、反和gauche 等不同的构象, 并且不同构象出现的几率会随着温度的改变而改变.

关键词: 离子液体电解液, 分子动力学模拟, 锂离子配位数, 离子扩散, 笼效应

Abstract: A molecular dynamics simulation was applied on a eutectic system (LiTFSI:urea) at a molar ratio of 1:3.6 at 25 ℃ and 50 ℃ to obtain the structural and dynamical properties. The results showed that there was almost no difference in structural properties at the above two simulation temperatures. The coordination number of the Li+ was about 5 and mainly coordinated by carbonyl oxygen atoms from urea and oxygen atoms from TFSI- anions. Also in the solvation shell of Li+, each TFSI- anion provided only one oxygen atom out of four to coordinate with Li+, and the TFSI- anions have trans, cis, and gauche configurations. The ratio of different configurations will change with temperature.

Key words: Ionic liquid electrolyte, Molecular dynamics simulation, Coordination number of the Li+, Ion diffusion, Cage effect